Field of the Invention
The present invention relates to an imaging device that generates and displays an image for the confirmation of focusing, and a control method thereof.
Description of the Related Art
As a digital camera, there is a well-known one including a so-called manual focus mode in Which a photographer can manually perform focusing adjustment (which is also referred to as “focus adjustment”), besides automatic focus using a phase difference detection system or a contrast detection system.
As a digital camera including a manual focus mode, there is a well-known one that adopts a method in which a reflex mirror is installed so as to be able to perform focus adjustment while confirming an imaged object and a split microprism screen that displays a phase difference by visual observation is used, or a method of confirming the contrast by visual observation.
Meanwhile, in a digital camera in which a reflex mirror widespread in recent years is omitted, there is no method of confirming an object image while displaying a phase difference since the reflex mirror does not exist, and it cannot help relying on the contrast detection system. However, in this case, it is not possible to perform contrast display over the resolution of a display device such as an LCD, and it cannot help adopting a method of performing partial enlargement and performing display.
Therefore, in recent years, a split image (second display image) used for the confirmation of focusing is displayed in a live view image (which is also referred to as “through image”) in order to facilitate work to perform focusing on an object by an operator at the manual focus mode. The split image is a result of dividing and displaying an image acquired by imaging object light subjected to pupil division, and indicates the phase difference of each image. Regarding a vertically divided split image, the upper and lower images of the split image are horizontally shifted when focusing is misadjusted. and the upper and lower images are not horizontally shifted in a state where focusing is adjusted. The photographer performs focusing by operating a manual focus ring such that the gap between the upper and lower images of the split image is removed.
In the digital camera described in Japanese Patent Application Laid-Open No. 2004-40740 (hereinafter referred to as PTL 1), an object image is taken in two measurement positions by moving a diaphragm in the direction vertical to the optical axis, and a split image is displayed in a live view image by the use of these two object images.
In the digital camera described in Japanese Patent Application Laid-Open No. 2001-309210 (hereinafter referred to as PTL 2), a value corresponding to the distance between the image surface of an object image and the light receiving surface of an imaging element is calculated as a shift amount, and a split image shifted in the right and left opposite directions according to this shift amount is displayed in a live view image.
The digital camera described in Japanese Patent Application Laid-Open No. 2009-147665 and Japanese Patent Application Laid-Open No. 2009-163220 (hereinafter respectively referred to as PTL 3 and PTL 4) include an imaging element formed by arraying a normal pixel for photographing and two kinds of phase difference pixels for the detection of focusing to receive object light subjected to pupil division on an imaging surface. This digital camera generates a photographed image on the basis of an output signal from the normal pixel and performs live view image display, and generates a split image on the basis of the output from each of two kinds of phase difference pixels and displays it in a live view image.